Locking metal inserts into cavities



Oct. 23, 1934.

LOCKING METAL INSERTS INTO CAVITIES R. F-. CLEMENT 1,978,340

Filed Feb. 17, 1934 zo'zerz' 1. 'czemenz' patented Oct. 23, 1934 um'reo srAr s LOCKING METAL INSERTS INTO cAvrrIEs Robert Frank Clement, Portslade England, as-

si'gn'or of one-half to Lymin'gton, England Application February 17,

John William Hewlett,

1934, Serial No; 711,761

In Great Britain September 9, 1933 1 Claims; (01; me -18s) This: invention relates tothe locking in position ofa metal insert in a cavity of a-structureand particularly to the locking of seating rings (for valves) in cavities formed in the cylinder 6 blocks or cylinder heads of internal-combustion engines-by arranging for the insert to be aforce fit in the cavity so that an integral radially-flexible portion of its periphery will spring radially into a recess in the cavity when the insert is- 10 forced axially into the cavity. The main object is to provide an improved: insert of this kind which will be inexpensive to manufacture and which can be very securely locked in position.

According to the main-feature otthe invention,

16 the radially-flexibleportionof the insert is separated' from the main: portion thereof except at its ends.

Ina preferred arrangement the insert, which is initially unst'ep'pe'd externally; is provided with a deep or through slit or slits transverse to the main axisottheinsert and extending only'partly' round the periphery of the insert to leave a sharp-edged, relatively flexible strip part which can expand radially into the recess inthe cavity' when the insert is forced axiallytherein. Preferably at least two such strip parts are used, these being symmetrically arranged and co -planar, whilst the corresponding recess formed in the cavity may be a single continuous one or conw stituted by several recesses. Furthermore, with a view to preventing the strippart from becoming deformed beyond its elastic limit whilst the insert is being forced into position, use may be made of a brass or other packing arranged adjacent to it,

the packing preferably extending radially outwardly not quite as far as the periphery of the strip part.

In the accompanying drawing:-

Figure 1 is a sectional elevation of a part of "a cylinder block of an internal-combustion engine with a valve-seating ring adapted according to the invention, the parts being much exaggerated for the sake of clearness;

,, 1 Figure 2 is a perspective view of the valve seating ring apart from the cavity in the cylinder block;

Figure 3 is an enlarged fragmentary view corresponding to that of Figure 1;

Figure 4 is a part-sectional elevation showing the manner in which the cavity in the cylinder block may alternatively be adapted, the valveseating ring being omitted in this figure; and

Figure 5 is a cross-section taken on the lin V-V of Figure 4. I

Like numerals indicate like parts throughout the drawing.

In the arrangement illustrated, for locking an insert in the form of a valve-seating ring 11 to a=cylindrical cavity 12 formed in a cylinder block 13, the ring 11, which is of circular periphery, the external surface of its walls being truly cylindrica-l andnot tapered, isaforce nt in the cavity 12,

having an overall diameter of between about 0.18 millimetres and 0.25 millimetres (dependent upon the size of the ring 11) greater than the bore of thecavity 12.

14 ,with apair of oppositely-arranged strip parts 15', 1 5 which in this case are formed by the provision ofthe saw-cut or like slits 16, 16 extending right through the seating ring and at right-angles to' its axis; These slits 16 are sufliciently near the bottom of the ring for the strip parts 15 to be slightly flexible compared with the rest of the ring and in manufacture care should preferably into the recess 18, whereupon the ring 11 becomes securely locked. in position by the engagement of the sharp edges 1'? against the sharp-edged wall of the recess 18. The dimensions of the recess 18 in a direction parallel to the axis of the seating ring should preferably be slightly greater than the corresponding dimension of the strip parts 15.

To obviate the tendency for the strip parts 15 to become permanently deformed while the ring 11 is being inserted into the cavity 12, use may be made of brass or other packings 19, 19, as shown, the outer edges of the packings preferably not extending radially quite to the outer edges of the slits 16. The packngs 19 may be a relatively loose fit in the slits 16.

In the modification illustrated by Figures 4 and 5, use is made of two oppositely-disposed undercut recesses 18a, 18a in the cavity 12 of the cylinder block of a size to receive the strip parts 15, instead of a continuous recess such as 18 being used.

By means of the invention, the secure locking of an insert, such as a valve-seating ring, can be effected in a very simple and inexpensive manner.

Although reference has been made above particularly ,to the locking of a valve-seating ring, it

The ring 11 is provided near its inner end, away from its machined seating face should be understood that the invention can be applied to the locking of cylinder liners, bushes,

core-plugs, or other circular or other elements to internal-combustion engines or other structures.

{If What I claim as my invention and desire to secure by Letters Patent of the United States is:-

1. A metal insert, which is a force fit in a cavity of a structure in which the insert is to be secured, the structure having a recess communicating with said cavity, the insert having an integral radiallyflexible peripheral portion which can spring radially into said recess when the insert is forced axially into said cavity, and said peripheral portion being separated from the main portion of the insert except at its ends.

2. A metal insert, which is a force fit in a cavity of a structure in which the insert is to be secured, the structure having a recess communicating with said cavity, the insert having an integral radiallyflexible peripheral portion which can spring radially into said recess when the insert is forced axially into said cavity, and the insert also having a deep slit in it along one edge of said peripheral portion.

3. A metal annular insert, which is a force fit in a cavity of a structure in which the insert is to be secured, the structure having a recess communicating with said cavity, the insert having an integral radially-flexible peripheral portion which can spring radially into said recess when the insert is forced axially into said cavity, and the insert also having a through slit in it along one edge of said peripheral portion.

4. A metal insert, which is a force fit in a cavity of a structure in which the insert is to be secured, the structure having a recess communicating with said cavity, the insert having at one end an integral radially-flexible peripheral portion which can spring radially into said recess when the insert is forced axially into said cavity, and said peripheral portion being separated from the main portion of the insert, except at its ends, by a slit substantially parallel to the said one end of the insert.

5. A metal annular insert, which is a force fit in a cavity of a structure in which the insert is to be secured, the structure having a recess communicating with said cavity, the insert having an integral radially-flexible peripheral portion which can spring radially into said recess when the insert is forced axially into said cavity, and

the insert also having a through slit along one edge of said peripheral portion and in a plane at right-angles to the axis of the insert.

6. A metal insert, which is a force fit in a cavity of a structure in which the insert is to be secured, the structure having a recess communicating with said cavity, the insert having an integral radiallyfiexible peripheral portion which can spring radially into said recess when the insert is forced axially into said cavity, and the insert having a deep slit in it along one edge of said peripheral portion leaving said peripheral portion sharpedged adjacent said slit.

7. A metal insert, which is a force fit in a cavity of a structure in which the insert is to be secured, the structure having a recess communicating with said cavity, the insert having an integral radially-flexible peripheral portion which can spring radially into said recess when the insert is forced axially into said cavity, the insert having a slit in it along one edge of said peripheral portion and said slit having in it a packing adapted to prevent axial deformation of said peripheral portion during the forcing of the insert into said cavity.

i 8. A metal annular insert, which is a force fit in a cavity of a structure in which the insert is to be secured, the structure having a recess communicating with said cavity, the insert having an integral radially-flexible peripheral portion which can spring radially into said recess when the insert is forced axially into said cavity, the insert having a through slit in it along one edge of said peripheral portion and said slit having in it a packing of arcuate shape.

9. A metal annular insert, which is a force fit in a cavity of a structure in which the insert is to be secured, the structure having a recess communicating with said cavity, the insert having an integral radially-flexible peripheral portion which can spring radially into said recess when the insert is forced axially into said cavity, the insert having a through slit in it along one edge of said peripheral portion, and said slit having in it a brass packing which does not extend radially outwardly as far as the periphery of the insert.

10. A metal annular insert, as claimed in claim 3, having a pair of similar, oppositely-arranged, co-planar peripheral portions.

ROBERT FRANK CLEMENT. 

